Technical Field
The instant disclosure relates to an LED illumination apparatus, in particular to an LED illumination apparatus having heat dissipating structures.
Related Art
Head lights of rail cars are different from typical illumination requirements. By considering the weight and speed of rail cars, its illumination is required to clearly illuminate objects far ahead on the rail, unlike typical indoor illumination for close distance and large area. Therefore, the light field associated with head lights of rail cars must meets specific regulations. Since for rail cars, its head lights must achieve a certain level of illumination for a specific distance and equivalent luminance, most rail cars today use conventional tungsten light bulbs. However, since tungsten light bulbs have a shorter service life and consume more power to reach certain illumination intensity, one of the major consequences is excessive temperatures.
Since tungsten light bulbs generate more heat, when the light bulbs are exposed continuously under excessive temperature condition, the service life of light bulbs is shortened. Other issues include increased replacement rate and maintenance fee.
With the advancement in light emitting diodes (LEDs), many LED-based products can replace existing tungsten light bulbs. But in order to meet the requirements of head lights for rail cars, since the head lights consume more power, the manufacturing price of the product is also higher. This scenario leads to higher sales price on the market. Since the illumination angle for the LED is only 180° , unlike 360° for tungsten light bulbs, the current remedy is to place a lens in front of the LED to concentrate light beams off the LED. However, during the manufacturing stage, because such practice requires concentrating each LED with the lens, the manufacturing process is more complicated relative to tungsten light bulbs. The manufacturing cost also increases since multiple lenses must be used.